Such test elements are used in order to determine body fluids, in particular for detection of a body fluid as such or of a component contained by it. For example, the determining of the body fluid takes place in connection with such a test element with an optical evaluation. Various optical measurement parameters can be evaluated here, for example the light emission in the form of a fluorescence or a phosphorescence or the light absorption. The optical measurement methods have proved to be expedient for some test elements in the form of test strips, in particular in connection with the examination of small blood volumes. They can also be used advantageously in ergonomically configured test strips.
For detection of the body fluid or of a component contained by it, the test elements regularly have a so-called detection zone, in which usually a chemical detection reaction of the body fluid or of one of its components takes place with a reaction system present in the reaction zone of the test element, so that one or more reaction products can be subsequently detected by measurement technology, in particular with the aid of an optical measurement.
In order to draw the correct conclusion with regard to the determining of the body fluid by means of the evaluation of the test element, quality and accuracy of the measurement process are of particular importance. Thus, the use of particular test elements is permitted only in temperature ranges which are specified for this, because an appropriate determining of the body fluid is only guaranteed with sufficient certainty in these temperature ranges. In a determining of blood sugar, for example the hematocrit value and therefore its influence on the measurement is temperature-dependent. In connection with test elements for determining blood sugar, therefore measurements and corrections derived herefrom in the evaluation of the measurement were proposed on the basis of the electrochemistry or the amperometry by means of the impedance method.
The document EP 1 411 346 A2 describes a method for the detection of an underdosing of an analytical test element and a system and a test element which are suitable for detecting an underdosing.
The document DE 10 2004 051 830 A1 describes a system for a luminescence detection of an analyte in a fluid sample (e.g. blood).
In the document EP 0 819 943 A2 an analysis system is described for the evaluation of analytical test elements.